I gotta agree with >>78035155
, Flash vs. Lex Luthor Brainiac is pretty great.
Lex-Brainiac solos the entire core JLA, Flash barely gets out of the rubble and Lex-Brainiac goes to kill him, trying to make the possible future of JSA being real.
He breaks out and Lex mocks him, saying that he (Flash) is going to beat Lex. And he runs... Only to come back a few seconds later with a Mach Punch. Que Flash running so fast he merges with the Speed Force, shreds Lex-Brainiac and seperates Brainiac (who has merged w/ Lex on a biological level) and kills/removes him before merging with the Speed Force entirely.
The added scene of them pulling him out of the Speed Force shortly afterwards is pretty cool.